According to the theory of plate tectonics, the
a. asthenosphere is divided into plates.
b. lithosphere is divided into plates.
c. asthenosphere moves over the lithosphere.
d. asthenosphere is strong and rigid.

B. lithosphere is divided into plates.

Explanation:

The theory of plate tectonics involves the splitting apart of the earth large lithosphere into sub parts when are called as plates. These plates are said to be glided over the hot mantle (the inner rocky layer above the core) due to the internal disturbance. These plates where expected to be like hard and rigid shells.

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.

a cold ice-tea.

pour in room temperature or cold water. cover the pitcher and refrigerate. steep white or green tea for 6 to 8 hours; steep black or oolong tea for 8 to 12 hours.jun 28, 2015